The pilot culls in Somerset and Gloucestershire are part of government efforts to curb the rise of tuberculosis in cattle and involved the shooting of free-running badgers at night. Ministers expected this to be less expensive than cage-trapping and shooting or the vaccination of badgers, but have so far refused to release the costs of the cull.

However, Gloucestershire's police and crime commissioner Martin Surl revealed on Twitter that policing costs for the Gloucestershire cull alone were £1.7m. In Somerset, the additional costs to police, such as overtime, were £738,985, which would be reclaimed from the government, Avon and Somerset chief constable Nick Gargan tweeted. When the normal duty hours of police staff were included, the Somerset total rose to £853,770.

The figures show the costs of policing the two culls, which had to be extended because not enough badgers were killed in the original six-week periods, equated to £1,300 per badger on average. The Association of Chief Police Officers (Acpo) originally estimated that policing costs would be about £500,000 annually for each four-year pilot.

The culls have already been criticised by scientists and by animal welfare and wildlife groups for being ineffective and expensive. Badger expert Prof Rosie Woodroffe calculated in June 2013 that badger vaccination would be less expensive.

Dominic Dyer, policy adviser for Care For The Wild, said: "The policing costs in Gloucestershire alone exceeded £1.7m, which is half a million more than the total cost of the Welsh government badger vaccination programme in 2012. It's now clear that the badger cull pilots have failed on scientific, humaneness and costs grounds."

But farmers said it was vital that everything was done to control and eradicate bovine TB. Andy Robertson, National Farmers' Union director general, said the behaviour of anti-cull activists had forced up the policing bill. "The culls were a perfectly lawful activity and their cost, which was borne by farmers and landowners, should not be confused with the cost of policing a group of people who tried to disrupt them," he said.

A spokesman for the Department for Environment, Food and Rural Affairs (Defra), which disputes the Care For The Wild cost estimates, said: "The costs of the badger cull pilots will be vastly outweighed by the impact that bovine TB is having on our farming industry and taxpayers. Each bovine TB cattle outbreak costs an average £34,000, and if left unchecked this disease will cost the taxpayer £1bn over the next 10 years."

The original impact assessment by Defra for the pilot culls, which relied on Acpo's estimates of policing costs, found that overall costs of culling were likely to be £880,000 more than the benefits in each cull zone.